The invention relates to molten metal sampling apparatus and is a further development of the subject matter of my U.S. Pat. Nos. 4,069,715 and 4,535,640. The prior art U.S. Pat. No. 4,069,715 shows a piggyback arrangement for joining two cardboard instrument carrying sleeves with refractory cement and staples or the like in side by side relationship to enable immersion in molten metal of the two side by side tubes to simultaneously obtain a metal sample and a bath temperature. This affords the opportunity of obtaining a bath temperature measurement with the thermocouple and also retrieving a sample of molten metal from the bath from a point adjacent to the sensor of the thermocouple with two independent pieces of equipment integrated together using one immersion tube. It is known to use combination samplers and thermocouples. U.S. Pat. No. 4,699,014 is an example of this art. These samplers are limited somewhat to the sample shapes and sizes of samples which can be confined and arranged in a workable fashion in one housing.
Although the apparatus disclosed in U.S. Pat. No. 4,069,715 was effective to accomplish the intended results it was never commercialized because there was no major cost saving as compared to using separate thermocouple tubes and separate sampling lances containing sample retrieving equipment. These piggyback samplers also had a large mass and displaced a large quantity of molten metal and were inconvenient to use and there was no quick sample release. They were not non-boiling and a large quantity of paperboard was exposed to the melt and gasified causing metal splash.
A large number of samplers presently include a heat sensor or thermocouple as well as a mold for molding a sample. Complex and expensive arrangements are required to isolate the molten metal from the cold junction of the thermocouple wires and the lead wires. The cold junction must also be isolated from the heat of the metal bath and the internally located hot sample. These samplers are difficult and time consuming to take apart for retrieval of the sample. In view of the fact that a great number of measurements are repeatedly taken in steel mills there is a need for low cost and easy to use sampling equipment because normally the sampler and sensor are consumed and not available for repetitive use. Accordingly, cost savings, safety and time and speed of operation are major factors in the construction of molten metal sampling equipment.